Crazed cop Garry Weddell planned to hang himself in shame after being accused of strangling his cheating wife Sandra.

His desperate plot was foiled when custody officers found a length of flex wrapped round his ankle.

But incredibly, despite the risk of him cheating justice, the 45-year-old Met inspector was granted £200,000 bail. And on Saturday the final grim act of the cruel drama was played out.

Vengeful Weddell shot dead mum-in-law Traute Maxfield, 70, after learning she was to give evidence against him. Then he drove to a shooting club and turned the gun on himself.

His suicide left his three children Kate, 13, Tom, 11, and Lucy, eight, orphaned. Last night relatives were still in shock.

Patsy Mowbray, mum-inlaw of Sandra's brother, said: "They've not only lost their mum but their grandmother as well. They loved her dearly.

"They're heartbroken. This is just terrible for them. Anyone who could do this is just evil."

Weddell's defence was told last week that widowed Mrs Maxfield was due to testify against him at his trial in May. The disclosure tipped the police inspector over the edge of reason.

It is thought he left his barrister brother Geoffrey's home in Woking, Surrey - where he lived - on Friday.

He then waited 24 hours before bursting into Mrs Maxfield's £1million house in the Hertfordshire hamlet of Gustard Wood and blasting her with an illegally-owned shotgun.

After the attack Weddell drove 10 miles in his Renault Laguna to Broomhills Shooting Club in Markyate.

He gained entrance even though he was not a member and his gun licence had been revoked.

Ex-soldier Weddell set off up a trail through woodland before emerging into fields at a spot known as The Rook.

There, he walked to a wooden shelter and shot himself in the head. His body was found at 11am. Officers went to Mrs Maxfield's home as she was listed as next of kin.

When they got no answer, a firearms team was called in. They entered and discovered the body of the devout churchgoer in her living room.

Danish-born Mrs Maxfield had lived alone at the property since the death of her husband William, 92, a year ago.

Friend Suzanne Locks, 72, said: "Poor Traute, what a dreadful end. She was very caring and devoted the last years of her life to looking after her husband."

Weddell, nurse Sandra, 44, and their children lived in a £450,000 home at Dunstable, Beds. A former neighbour said: "They seemed like a perfect family."

But in December 2006 the inspector found Sandra had been having an affair.

When he confronted her, she said she wanted to end their 23-year marriage. Four weeks later Sandra went missing.

She was found dead in the garage of her home with a cable tie round her neck with an apparent suicide note by her body. But there were bruises on the corpse. In June Weddell, an officer for 25 years, was accused of her murder.

The officer, who had been allowed weekly supervised visits to his children at their uncle's home, was originally remanded in custody by Luton court.

Prosecutors claimed that Weddell, a Police Federation representative, killed Sandra because he feared losing his home, his children and half his pension.

A later application for bail was refused when police discovered the flex as Weddell was transferred to court.

But he was eventually freed on bail in September at Ipswich crown court after his "soul mate" brother agreed to put up £200,000 surety. Yesterday Geoffrey refused to comment.